条斑紫菜优良品系(LC-14)的筛选与特性分析

从条斑紫菜(Pyropia yezoensis)绿色突变体和红色突变体种内杂交产生的F_1叶状体中,分离出新品系LC-14。该品系的F_1叶状体在生长速度和品质等方面均显著优于条斑紫菜野生型栽培品系(WT)。日龄70 d的叶状体平均长度和湿重,LC-14品系分别为106.53 cm和3.07 g,分别是WT品系的4.39和10.27倍。培养至第55天,LC-14品系的3种主要光合色素(叶绿素a、藻红蛋白和藻蓝蛋白)含量分别为9.85 mg/g、52.09 mg/g和23.26 mg/g,分别比WT品系提高了65%、65%和49%,而其藻体的平均厚度(20.89μm)反而降低了32%。此外,LC-14品系的壳孢子放散总量为761.32×10~4 ind/壳,是WT品系的1.28倍。上述结果表明,LC-14品系具有生长快、品质优、壳孢子放散量大的优点,藻体颜色与野生色(棕褐色)相近,是条斑紫菜的优良品系,有望在生产中应用。

Selection and characterization of the improved strain (LC-14) in Pyropia yezoensis (Bangiales, Rhodophyta)

Pyropia yezoensis belongs to Bangiaceae, Bangiales, Protoflorideae, Rhodophyta. For its high commer-cial and nutritional value, it becomes one of the most important seaweed cultivars in the coastal area of northern China. For decades, because of incorrect breed conservation and inbreeding, the germplasm of this species had been serious degenerated, which resulted in a decline of yield and quality such as slower growth rate, thicker, ma-tured earlier and more susceptible. These problems seriously affected the economic benefits of the cultivation. Therefore, breeding new varieties of P. yezoensis is greatly significant for the sustainable development of this industry. In order to select a new variety of P. yezoensis with faster growth rate, higher quality and wild-type color, intraspecific hybridization of the green-type pigmentation mutant and red-type pigmentation mutant in P. yezoen-sis was conducted to isolate an improved strain (LC-14) from the recombinants. After cultured for 70 days, the mean length and wet weight of F1 blades in LC-14 strain was 106.53 cm and 3.07 g, which was 4.39 and 10.27 times of the wild-type strain (WT), respectively. The results indicated that the improved strain had higher growth advantages, and the higher yield compared with WT strain. Being cultured to 55 days, the contents of three major photosynthetic pigments (chlorophyll a, phycocyanin and phycocyanin) in LC-14 strain were 9.85 mg/g, 52.09 mg/g and 23.26 mg/g, with an increasing by 65%, 65% and 49% when compared with WT strain respectively. Mean-while, the thickness of blades of LC-14 strain was 20.89 μm, which is 32% thinner than that of WT strain. These results showed that the taste was better, and the quality was higher than those of the WT strain. In addition, the daily amount of conchospores released from LC-14 strain could be more than 2 million and the total amount of conchospores for successive 20 days was 761.32×104, which was 1.28 times compared to WT strain. The results showed that conchospores released were sufficient during the stage of seedlings collection and the productive re-quirements of releasing amount could be fully satisfied. In summary, all of these results above confirmed that LC-14 strain with fast growth rate, high quality, large amount of conchospores and similar color with wild-type was suitable for cultivation, which completely achieved the original intention of this study. Therefore, LC-14 strain is expected to become a new improved variety through the national approval and be applied in the practical production in the near future.